1. Field of the Invention
The present invention relates to the preparation of flavors useful for candy and chewing gum, and more particularly to the preparation of such flavors in a form that provides improved shelf stability and flavor sensation.
2. Description of the Prior Art
While a wide variety of flavors have been formulated for incorporation into candies and chewing gums, one of the problems attending the development of these products in novel flavor forms, has been the tendency of the flavor to diminish rapidly in intensity, and thereafter disappear within a relatively short period of time. This deficiency is most noteworthy in the instance of chewing gums, as flavor loss frequently occurs within the first four to five minutes of chewing.
The similar problem is observed in the instance where the product is stored for a period of time between manufacture and consumption. The flavors likewise tend to exhibit undesirably limited shelf stability, and, in some cases, may diminish to an unacceptably low level within one month after storage.
Several efforts have been made to remedy the aforenoted deficiencies by the preparation of flavors in encapsulated forms. Specifically, U.S. Pat. Nos. 3,795,744 and 3,826,847, by Ogawa et al., encapsulate a variety of flavors by homogeneously dispersing the flavors in a solution of water soluble high molecular weight compounds, such as polyvinyl esters, cellulose derivatives, and the like. The approach taken in Ogawa et al. possesses certain drawbacks, in that the high molecular weight material must be combined with plasticizers and solvents, before the addition of the flavor, and precipitation of the encapsulated flavor beads is accomplished by the addition of a hydrocarbon solvent such as hexane, which must be thereafter volatized off. Thus, in addition to introducing undesirable compounds, the Ogawa et al. preparation is unduly complex.
Further activity in the area of encapsulation of food additives, has centered around the efforts to prolong the stability of the artificial dipeptide sweetener known commonly as APM. In particular, U.S. Pat. No. 3,928,633 to Shoaf et al. proposes to encapsulate APM by dispersion within a material capable of being processed by hot melt techniques, and thereafter cooled to form an amorphous matrix containing the APM. The patent discloses, as one of the acceptable hot melt ingredients, polyhydric alcohols such as sorbitol. While the disclosure of Shoaf et al. may be relevant to the encapsulation of APM, the temperatures at which the patented procedure operates, are too high for the encapsulation of many desirable flavors, which would be lost by volatization, if they were incorporated into the encapsulant matrix. Sorbitol itself, congeals at a temperature that is too high to permit it to operate individually as an effective encapsulant.
Also, the chemistry of APM differs from that of food flavors, and analogies in operation and effect of encapsulants may not be properly drawn.
A specific preparation of sorbital encapsulated flavors is disclosed in U.S. Pat. No. 2,904,440, to Dimick et al. The patentees attempt to improve shelf stability by pretreating the flavor essence to remove certain low molecular weight alcohols, and compounds that behave like such alcohols. The patentees suggest that these alcohols inhibit the solidification of the sorbitol matrix, and attack the solidified matrix to cause it to break down and release the flavor.
Apart from this pretreatment of the flavor, however, Dimick et al. conform to the prior art, as they merely incorporate the treated flavor into melted sorbitol, add some seed crystals of sorbitol, and cool the melt to about 80.degree. C. to commence crystallization. The nature of this processing, however, fails to encapsulate and safely retain the flavor completely within the sorbitol matrix, and the Dimick et al. preparation is inoperable for those flavors that volatize at the processing temperatures above 70.degree. C.
A need therefore exists to develop a method and associated product that extends the shelf life of a wide variety of flavorings, without introducing undesired synthetic compounds to the ultimate food product, and which may be accomplished with a minimum expenditure of materials, energy and time.